1987 190 2L Very little interior heat-help!

[Mikesmerc]

My 87 190 2L is emitting very little heat to the interior. Lots of air but not hot enough for winter conditions. I fitted a new heater rad and worked perfectly for about 2 months, but am now back to square one. I flushed the system, checked the valves,fan and the air control dampers, all seem to be working fine. Is there something else I should check?
I would appreciate any suggestions/comments.
Regards
Mike

 

[jack-n-gill]

Hi Mike
Does your engine warm up quickly-80 degrees in 1 to 2 miles?
If not you nay need to renew the thermostat as the engine may be overcooled and thus the water temp is too low to provide enough heat for the exchanger to function efficiently.

 

[Mikesmerc]

Warms up quiet quickly to approx 80deg. Its obviously lack of circulation or is there some sort of cabin temp stat faulty.
Thanks for your reply Jack
Regards
Mike

 

[jack-n-gill]

Cool Customer

Mikesmerc
I don't think there is a cabin stat as there are no temperature settings on the heater controls. I'll have a look in the Haynes Manual tonight and see if there is anything that may be stopping it working.
Just a thought, have you tried setting both left and right cabin heater controls to max to see if one is working better than the other?

 

[jack-n-gill]

Me again Mike.
Went through the manual last night, not too helpful as there isn't a description of exactly how the system works.
It seems that the heater controls use vacuum to operate a valve to let hot water into the heat exchanger. Only thing I can suggest is that one of the hoses, they are only about 6mm dia, is either split or blocked, or the diaphragm in the vac. valve is knacke- oops, damaged.
Sorry can't be more help.

 

[TimN]

It might be that the incoming air is able to bypass the heater matrix. When you reassembled the heater box the matrix should be held in position and packed tight by something like felt.

The only other thing that I can think of is that there is an airlock stopping the hot water from circulating around the heater matrix. Disconnect the hoses and plug the garden hose in. You may need a couple of jubilee clips and a peice of 15mm plumbers copper tube. Then give it full mains pressure through the heater matrix. Ensure that the water coming out of the heater matrix does not spill over the engines electrics.

 

[mofo]

i have exactly the same problem.
but one side is hotter than the other.

in my case i think its the vidcous fan and the idiot who had the car before me welded the damn thing so its always on hence water aint getting hot enough.

the temp gauge in the dash never goes above 85 in the summer.

Some also told me that It could be the matrix heater behind the dash but I really doubt this.

i hate driving this car in the winter